HR: 1340h
AN: A53A-0857    [Abstracts]
TI: A Regional Climate Model Simulation of U.S. Soil Temperature and Moisture during 1982-2002
AU: * Zhu, J
EM: zjh@uiuc.edu
AU: Liang, X
EM: xliang@uiuc.edu
AB: The MM5-based regional climate model (CMM5) simulation of the United States soil temperature and soil moisture annual cycle and interannual variability during 1982-2002 driven by the NCEP-DOE AMIP II reanalysis (R-2) is compared with observations and outputs from the R-2 and North American Land Data Assimilation System (NLDAS). The comparison demonstrates that the CMM5 has a pronounced downscaling skill. The CMM5 realistically simulates a warming trend of annual mean soil temperature during the past 20yr with a slightly smaller rate than observations. The seasonal mean trends are also realistic except that a decreasing trend in fall is opposite to observation. The CMM5 simulated annual cycle and interannual variations of soil moisture are in good agreement with measurements in Illinois (whole year) and Iowa (April-November). The largest CMM5 differences of soil temperature from observations and of soil moisture from NLDAS outputs are identified over the Great Plains. Although such soil temperature differences may be associated with the CMM5 biases in surface air temperature, the soil moisture differences do not correspond to precipitation differences. The result emphasizes the need for more comprehensive study on model evaluation and bias understanding of soil temperature and soil moisture.
DE: 3309 Climatology (1620)
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting